None of the DUP's 10 MP's attended the debate with deputy leader Nigel Dodds saying that the debate was of "no significance whatsoever".

Speaking in the Commons, Lady Hermon said that no Brexit deal would result in a hard border in Ireland this could see the return of violence.

"If we have no deal, we will inevitably have a hard border in Northern Ireland and we will see the return of violence in Northern Ireland," she said.

Nicky Morgan and Ken Clarke were among the senior pro-EU Tories who urged the Prime Minister to retain the option of a customs union between the UK and EU, amid concerns over the impact of major changes to peace in Northern Ireland.

Former education secretary Mrs Morgan advised her party that they “will not be forgiven for a generation” if they ignore the “evidence for peace” in Northern Ireland and undermine business and financial security.

MPs approved a non-binding motion, which called on the Government to include as an objective in Brexit negotiations the option of establishing “an effective customs union” between the UK and EU, without a formal vote.

But very few Brexit-backing MPs attended the debate, which emerged after 10 select committee chairs moved a motion on the issue.